2.9 Optical Fiber Cables
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2.9.2 Designs of Indoor Optical Cables
Indoor cables can be used for interconnecting instruments, for distributing signals
among office users, for connections to printers or servers, and for short patch cords
in telecommunication equipment racks. The three main types are described here.
Interconnect cable serves light-duty low-fiber count indoor applications such as
fiber-to-the-desk links, patch cords, and point-to-point runs in conduits and trays.
The cable is flexible, compact, and lightweight with a tight-buffered construction.
A popular indoor cable type is the duplex cable, which consists of two fibers that
are encapsulated in an outer PVC jacket. Fiber optic patch cords, also known as
jumper cables, are short lengths (usually less than 2 m) of simplex or duplex cable
with connectors on both ends. They are used to connect lightwave test equipment
to a fiber patch panel or to interconnect optical transmission modules within an
equipment rack.
Breakout or fanout cable consists of up to 12 tight-buffered fibers stranded around
a central strength member. Such cables serve low-to-medium fiber-count applications where it is necessary to protect individual jacketed fibers. The breakout cable
allows easy installation of connectors on individual fibers in the cable. With such a
cable configuration, routing the individually terminated fibers to separate pieces of
equipment can be achieved easily.
Distribution cable consists of individual or small groupings of tight-buffered
fibers stranded around a central strength member. This cable serves a wide range of
network applications for sending data, voice, and video signals. Distribution cables
are designed for use in intra-building cable trays, conduits, and loose placement in
dropped-ceiling structures. A main feature is that they enable groupings of fibers
within the cable to be branched (distributed) to various locations.
2.9.3 Designs of Outdoor Optical Cables
Outdoor cable installations include aerial, duct, direct burial, and underwater applications. Invariably these cables consist of a loose-tube structure. Many different designs
and sizes of outdoor cables are available depending on the physical environment in
which the cable will be used and the particular application.
Aerial cable is intended for mounting outside between buildings or on poles or
towers. The two popular designs are the self-supporting and the facility-supporting
cable structures. The self-supporting cable contains an internal strength member that
permits the cable to be strung between poles without using any additional support
mechanisms for the cable. For the facility-supporting cable, first a separate wire or
strength member is strung between the poles and then the cable is lashed or clipped
to this member.
Armored cable for direct-burial or underground-duct applications has one or more
layers of steel-wire or steel-sheath protective armoring below a layer of polyethylene
83
2.9.2 Designs of Indoor Optical Cables
Indoor cables can be used for interconnecting instruments, for distributing signals
among office users, for connections to printers or servers, and for short patch cords
in telecommunication equipment racks. The three main types are described here.
Interconnect cable serves light-duty low-fiber count indoor applications such as
fiber-to-the-desk links, patch cords, and point-to-point runs in conduits and trays.
The cable is flexible, compact, and lightweight with a tight-buffered construction.
A popular indoor cable type is the duplex cable, which consists of two fibers that
are encapsulated in an outer PVC jacket. Fiber optic patch cords, also known as
jumper cables, are short lengths (usually less than 2 m) of simplex or duplex cable
with connectors on both ends. They are used to connect lightwave test equipment
to a fiber patch panel or to interconnect optical transmission modules within an
equipment rack.
Breakout or fanout cable consists of up to 12 tight-buffered fibers stranded around
a central strength member. Such cables serve low-to-medium fiber-count applications where it is necessary to protect individual jacketed fibers. The breakout cable
allows easy installation of connectors on individual fibers in the cable. With such a
cable configuration, routing the individually terminated fibers to separate pieces of
equipment can be achieved easily.
Distribution cable consists of individual or small groupings of tight-buffered
fibers stranded around a central strength member. This cable serves a wide range of
network applications for sending data, voice, and video signals. Distribution cables
are designed for use in intra-building cable trays, conduits, and loose placement in
dropped-ceiling structures. A main feature is that they enable groupings of fibers
within the cable to be branched (distributed) to various locations.
2.9.3 Designs of Outdoor Optical Cables
Outdoor cable installations include aerial, duct, direct burial, and underwater applications. Invariably these cables consist of a loose-tube structure. Many different designs
and sizes of outdoor cables are available depending on the physical environment in
which the cable will be used and the particular application.
Aerial cable is intended for mounting outside between buildings or on poles or
towers. The two popular designs are the self-supporting and the facility-supporting
cable structures. The self-supporting cable contains an internal strength member that
permits the cable to be strung between poles without using any additional support
mechanisms for the cable. For the facility-supporting cable, first a separate wire or
strength member is strung between the poles and then the cable is lashed or clipped
to this member.
Armored cable for direct-burial or underground-duct applications has one or more
layers of steel-wire or steel-sheath protective armoring below a layer of polyethylene